The second change seems anodyne enough, but the first significantly changes Luke’s motivation IMO since he now decides to become a Jedi without any information about his father’s wishes. Because of this, the revelation in ESB could have less of an impact because Luke is becoming a Jedi more of his own volition and less because he believed that his father wanted him to follow in his footsteps.
That’s what I think too, even if it’s a lie I feel like “your father” works better than “I”.